NEW YORK - Rafael Nadal breezed into the fourth round of the US Open on Saturday, moving nearer a potential showdown with Roger Federer, while Victoria Azarenka and Ana Ivanovic battled their way into the last 16.
Nadal, a 12-time Grand Slam champion who has won nine titles since returning in February from a seven-month injury layoff, stretched a career-best hardcourt win streak to 18 matches by beating Croatian Ivan Dodig, 6-4 6-3 6-3.
"I started the match with the right intensity," Nadal said. "I think I played my best match of the week so far."
Second-seeded Spaniard Nadal, who completed a career Grand Slam with his 2010 US Open crown, and Swiss star Roger Federer, in his lowest Grand Slam seeding since 2002 at seventh, have never played at the US Open but could meet in the quarter-finals.
Federer, seeking his 17th Grand Slam title and sixth US Open crown, will face French left-hander Adrian Mannarino, who has never beaten a top-10 foe, in a night match at Arthur Ashe Stadium.
Nadal, who has not lost his serve in three matches, took command early and connected on 65 per cent of his first serves and fired 37 winners in improving to 56-3 this year.
"I have to improve a little bit of everything to keep going in the second week," Nadal said. "To win matches if you are not playing your best, it's impossible."
Either US 13th seed John Isner or German 22nd seed Philipp Kohlschreiber will be next for Nadal, who missed last year's Open due to injured knees.
Two-time Australian Open champion Azarenka escaped an upset bid while Daniela Hantuchova saved four match points to advance, but Grand Slam winners Petra Kvitova and Svetlana Kuznetsova were ousted.
Belarus second seed Azarenka, who lost to top seed Serena Williams in last year's final, outlasted French 26th seed Alize Cornet 6-7 (2-7) 6-3 6-2.
Cornet denied Azarenka on 10 of 11 break chances in the first set, but could not hold on after dominating the tie-breaker.
"The first set Alize played really well and I made too many mistakes," said Azarenka.
"I wasn't patient and didn't convert my chances. In the second set I started to take advantage of my opportunities and that made the difference."
Next up for Azarenka will be Serbian 13th seed Ana Ivanovic, the 2008 French Open champion who rallied past American Christina McHale 4-6 7-5 6-4.
Czech seventh seed Kvitova, the 2011 Wimbledon champion who was diagnosed with a virus on Friday, made 27 unforced errors and seven double faults in losing to 81st-ranked US wildcard Alison Riske 6-3 6-0.
Riske will next face 48th-ranked Slovak Hantuchova, who struggled with a sore right shoulder but outlasted Ukraine-born Israeli qualifier Julia Glushko, who had not won a tour match until this week, by 3-6 7-5 7-6 (7-4).
Russian 27th seed Kuznetsova, the 2004 US Open and 2009 French Open champion, made 35 unforced errors in losing 7-5 6-1 to Italy's 83rd-ranked Flavia Pennetta, who had dropped their five prior career matchups.